A strong 6.6-magnitude earthquake and a series of tremors have rattled the north-east coast of Japan. At least five quakes struck the same area south-east of the port of Hachinohe this morning. No tsunami warnings were issued, but the Japan Meteorological Agency advised that there might be some changes in sea levels. There were no immediate reports of damage or casualties.In China also, a 5.5-magnitude earthquake jolted western province of Xinjiang today, damaging over 50 houses in the region, but no casualties were reported.The epicentre, with a depth of 6 km, was about 75 km from the county in the far western Xinjiang Uygur Autonomous Region.